Commercial tape is different - key modified (7)
I believe the answer is:
adapted
'modified' is the definition.
(similar in meaning)
'commercial tape is different key' is the wordplay.
'commercial' becomes 'ad' (abbreviation for advertisement).
'is different' is an anagram indicator.
'key' becomes 'd' (musical key).
'tape' with letters rearranged gives 'apte'.
'ad'+'apte'+'d'='ADAPTED'
(Other definitions for adapted that I've seen before include "Became adjusted" , "Changed to suit anoter purpose" , "Made suitable for new purpose" , "Turned to new purpose" , "Modified to suit" .)